Oscilloscope doubles as a serial terminal

PC-based USB oscilloscopes are fast becoming all the rage. [Matt Sarnoff’s] Terminalscope takes the reverse approach, adapting an oscilloscope into a full serial terminal. You may have seen something similar before in the Dutchtronix/SparkFun O-Clock, but [Matt’s] project goes one further by adding a PS/2 keyboard port for full bidirectional serial communication, and with much sharper display resolution to boot.

The mostly VT-100 compatible Terminalscope is built around two AVR microcontrollers: an ATmega328P runs full-tilt to generate the video signal and handle serial I/O, while an ATtiny45 handles keyboard input to avoid interrupting the ’328’s duties. Rather than vector trace each character, a raster-scanning approach is used: the beam follows a fixed X/Y path (like a television), while modulating the Z input (beam intensity) to form an image. The device can be connected to a PC via serial port or USB-to-TTY adapter, or directly to another microcontroller to debug serial output.

We recently showed an oscilloscope being used as a multichannel digital logic display. The Terminalscope provides yet another use for this essential bench tool and could nicely round out a “poor man’s” testing setup. The schematic and full source code are available for download.

25 thoughts on “Oscilloscope doubles as a serial terminal”

That’s very clever. I can easily see the point of having one less screen cluttering up the workbench.

Shame it’s not vector glyphs. That would be the icing on the cake. http://cathodecorner.com/ has a neat method for generating roundy characters without the jaggies you normally get using straight X-Y DACs.

therian: it’s more like why use an old black and white tv as a computer monitor when you have a monitor. it’s about the knowledge required to successfully do it. now this knowledge can be applied elsewhere.

Reminds me of the time me and some friends managed to play Doom on a high-end Tektronix oscilloscope at uni (It was running Windows XP with the oscilloscope software set to auto-run). There’s a video on YouTube somewhere of it: a few commenters said it was fake or a case-mod but I can assure you it was definitely real.

One practice use would be that you only need to bring your scope with you if your going somewhere. Either way, if you have a oscilloscope why not do it for the off chance it comes in handy. Pretty cool stuff if you ask me.